A Comparison of Clinical and Ultrasound Estimation of Fetal Weigth at a Secondary Health Care Facility in Nigeria

Abstract

Background: Several methods have been used to estimate fetal birth weight; however two methods seem to be more widely accepted by obstetricians - ultrasound estimation and clinical estimation by palpation

Objective: This study sought to determine the accuracy and correlation of clinical and ultrasound estimation of fetal weight at the Central hospital, Warri, Delta state.

Methods: Sixty pregnant women in latent phase labour, very early first stage labour, or for induction of labour were selected for the study. Clinical  estimation of fetal weight and an independent blinded ultrasound assessment of the fetal weight was done. Fetal weigth estimates obtained were  compared with the actual weight at birth. Accuracy of estimates and correlation with actual birth weight was calculated.

Results: The Clinical method had a greater mean absolute error (SD) of estimation of the actual birth weight when compared with the ultrasound scan  method (391.08gm vs 63.00 gm). The mean difference between the methods was statistically significant (p = <0.001). The Clinical method also had a  greater mean percentage error (SD) of estimation of actual birth weight of when compared to the ultrasound methods (12.50% vs 1.2%). The mean  difference between the methods was statistically significant (p = <0.001). Furthermore, the ultrasound method of birth weight estimation had a greater positive correlation (0.703) with the actual birth weight than the clinical method. This was statistically significant p = <0.001

Conclusion: Ultrasound estimation of fetal birth weight is better than clinical estimation done by residents at the Central hospital, Warri.